change cached data manually

Dear Sir,
I enable your module file cache and write these line in setting.php

$conf['cache_backends'] = array('sites/all/modules/filecache/filecache.inc');
$conf['cache_default_class'] = 'DrupalFileCache';

and I found a new folder created in sites\default\files\.ht.filecache with all cached filed

I change these file (cache_field-field node 1) manually to check if he read from data or not

and make a new page and called node_load(1)

I found that page return back to original (so he read from database not the file)
Is there is something wrong in my configuration

Thanks